Disposable mixing syringe

ABSTRACT

A disposable mixing syringe is described. It comprises a barrel containing a removable centerboard dividing it into two compartments each for receiving one component of a mixture to be formed and terminating in a small orifice. The opposite barrel end is open and adapted to receive a slotted cup, through the slot of which passes an extension of the centerboard. Removing the centerboard allows mixture of the components by inserting a mixing tool, after which a suitable plunger is provided to expel the mixed contents through the orifice.

United States Patent [191 Baskas et a1.

DISPOSABLE MIXING SYRINGE Morris J. Baskas; Harry Kaufman, both of NewRochelle, NY.

Dentipressions Inc., New York, NY

Apr. 9, 1973 Inventors:

Assignee:

Filed:

App]. No.:

US. Cl. 259/37, 128/218 M, 206/47 A, 259/60, 259/D1G. 20

Int. Cl. B0lf 7/00, A61k5/02. Field of Search.... 259/37, 36, 60, 61,DIGQZO; 128/218 M, 272; 206/47 A; 222/135 References Cited UNITED STATESPATENTS 3/1929 Toch 206/47 A X 1/1962 Van Sick1e.... 128/218 M 2/1963Hunt, Sr 128/218 M 'June 11, 1974 3,247,529 4/1966 Benton 206/47 A X3.404.811 10/1968 Cernei 206/47 A X 3.537.605 11/1970 Solowey 206/47 A XPrimary Examiner-Edward L. Roberts Assistant Examiner-G. R. Robinsonthrough the orifice.

8 Claims, 6 Drawing Figures 1 DISPOSABLE MIXING SYRINGE This inventionrelates to a combination mixing syringe and disposable dispensing deviceespecially adapted for providing mixtures of constituents having roughlyequal proportions. t

The invention is especially useful for mixing heavy or highly viscousmaterials. In one instance, to make epoxy type cements, one usuallymixes equal'proportions of a highly viscous resin and a highly viscoushardener or catalyst. After thorough mixing, the ,cementis ready to beapplied to the articles to be joinedfFor use in making dental models,-the epoxy has to be introduced to an impression. Centrifuging isnecessary to ensure thorough contact because of the high viscosity.Thorough mixing of correct proportions of the epoxy constituents is noteasily accomplished following the prior art, because of the difficultyof measuring out equal proportions of the heavy liquids from largersupplies and of mixing same. Moreover,'centrifuging causes distortion ofthe model. In another instance involving a known dental impressiontechnique, a rubber type impression material is formed by mixing equalproportions of a suitable rubber-type resin and a suitable catalyst andthe mixture dispensed into a tray which is pressed onto the patients jawto form an impression of the teeth and gum. Particularly in the lattercase, a predetermined amount of mixture is required to fill the tray.Present techniques for accomplishing the latter are cumbersome and timeconsuming because they place on the dental practitioner the burden ofmeasuring equal proportions of the constituents taken individually fromlarge tubes, and then completely mixing them on a slab, after which themixture is transferred by hand directly to the tray. Inan alternatemethod, the mixture is placed in a syringe and then extruded onto thepatients teeth. In the latter case, difficulties are encountered intransferring the highly viscous paste to the syringe, much waste occurs,and it is generally a messy and cumbersome procedure.

The main object of the invention is a device in which the correctproportions of a two-component mixture are pre-established thoughmaintained separately, and bywhich they can be readily mixed, and themixture then readily applied in an appropriate manner to an object tobecoated.

This and other objects and advantages of the invention as will appearhereinafter are achieved, in accordance with the invention, by adisposable syringe having at one end an orifice through which themixture may be expelled and having its opposite, end open. A removablecenterboard-extends down the center of the syringe in engagement withthe syringe walls, forming two adjacent, side-by-side compartments.Oneeach of the mixture constituents is loaded into each of thecompartments, where theyare stored maintained separate from one anotherby the centerboard..The centerboard extends up above the syringe openend, which is then closed off by disposing a closure member in theopening and containing a slot foraccommodating the centerboardextension. The closure which may be a foil not only'serves to close offthe syringe but also acts to wipe off the centerboard during itsremovalwhen the mixture is to be formed. A mixing tool is then inserted throughthe open end to mix the constituents together within the syringe, andafter removal of the mixing tool .a suitable plunger is insertedin-theopen end to expel the mixture through the orifice.

A further feature of the'invention is the provision of one ormore smallprojections or protuberances at the bottomof the centerboard whichfunction to engage and cause lifting out and removal of the foil closuresimultaneously with removal of the centerboard.

A'further feature is construction of thefoil in the shape of a cup whichseats in the open barrel end. This construction not only simplifiesassembly, but also allows with a modified centerboard retention of thefoil during the mixing operation.

Among the advantages of the novel device of the invention are low-costmanufacture, pre-measured proportions of the ingredients ensuring theoptimum mixture composition, rapid and intimate mixing oftheconstituents, disposability due to low cost, and minimum timeexpenditure by the user.

Several exemplary embodiments of the invention will now be described ingreater detail with reference to the accompanying drawing, wherein:

FIG. 1 is a cross-sectional, elevational view of one form of combinationsyringe andmixing device of the invention;

FIG. 2 is a top view of the device shown in FIG. 1;

FIGS. 3-5 are cross-sections of the device of FIG. 1 showing how it isused;

FIGS. 6 and 7 are cross-sectional views of a modification.

One form of the invention is shown in cross-section in'FIG. 1. Itcomprises adisposable syringe '5 comprising a generally cylindricalbarrel 6 tapering down at its bottom end to a nozzle 7 havingan orifice8. It maybe constituted of any suitable plastic resin. The upper end isformed with an enlarged flange 9 by which the syringe may be manuallyheldor secured to-a suitable pressure-generating device. The top surface'10 of the flange is generally flat. The nozzle end 7 can be closed offwith a removal cap 11 which may be held on'the nozzle by a'friction fit,or it may be closed off by any other device, such as a pin, or peel-awayclosure, or the like.

A centerboard 13 made for example of plastic is disposed in-the centerof the barrel 6. The centerboard 13 comprises a flat member whoseedgesengage'the inside surfaces of the barrel walls. The thickness of thecenterboard 13 is such that its bottom edge closes off the entrance tothe nozzle 7. The centerboard '13 divides the barrel into two isolated,side-by-side vertical compartments l4, 15 of equal volume with eachhaving a semi-cylindrical shape.

Amemberlfi closes off the top open-end of the barrel. In a-preferredform, the member is a foil which comprises a thin metal or plasticcup-shaped member having a flange portion 17 which seats on the syringeflange 9 and a depending portion 18 which seats within the barrel 6. Thefoil contains a transverse slot 19 which extends across the full widthup to the barrel walls. The slot 19 has a width and length sufficient toaccommodate the centerboard with a close fit and yet .willallow thelatter to slide relative to thefoil. Atfthe bottom of the centerboard,at opposite sides, areprovided small projections or protuberances 20whose spacing is larger than the slot width. The centerboard 13, at itsupper portion extending above the barrel, is provided with a hole 21 toreceive afinger or thumb of the user.

In operation, the centerboard 13 is seated within the syringe barrel 6and then each of the compartments 14, 15 is loaded with the properproportions of two constituents which make up the mixture to be formed,shown respectively at 2 2, 23. Then, the foil member 16 is placed inposition. The entire top can then be secured by plastic tape or packagedin a tight plastic stretch material to hold the assembly in the positionillustrated in FIG. 1 with the centerboard separating the twoconstituents and preventing their reaction. In that form, the loadedsyringe can be distributed to the user who will retain same until readyfor use.

In use, the skin package is removed, and'then while holding the foil 16in place with one hand, the centerboard 13 is removed with the otherhand. During removal of the centerboard through the slot 19, anyconstituents adherent to the centerboard sides are wiped off the boardby the foil and fall back into the syringe barrel to maintain thedesired proportions. When the projections 20 reach the foil, the userreleases the latter and the foil, closure 16 is completely removed withcomplete removal of the centerboard, as illustrated in FIG. 3. Next,asuitable mixing tool such as a spatula canbe inserted through the openbarrel end and the constituents thoroughly mixed to form the desiredmixture 26, as shown in FIG. 4. Then the mixing tool 25 is removed, asuitable plunger 27 with attached rod 28 inserted through the open end,the nozzle cap 11 removed, and by driving the plunger downward, as shownin FIG. 5, the thoroughly mixed constituents 26 can be extruded anddispensed as desired. After use, the syringe may be disposed of.

FIG. 6 shows a construction employing a modified centerboard 30 free ofthe protuberances at its bottom. The parts of this modification thatremain the same as that of FIG. I bear the same reference numerals. Inthis case, when the centerboard 30 is removed, as before, the foil cup16 acts to wipe the sides clean but now the centerboard can be removedwithout removing the foil cup 16. Then, a mixing tool in the form ofaflatspatula 31 with flat or serrated edges 32 as shown in FIG. 7 isinserted through the slot 16 (the view in FIG. 7 is at right angles tothat of FIG. 6) and the two constituents can be .thoroughly mixed byrotating the mixer with the foil 16 in place to prevent loss of anycontents. When the mixer 31 is rotated, the foil cup 16 will rotate withthe mixer. After complete mixing, the tool 31 is removed, the foil cup16 is removed, and then the plunger 27 as shown in FIG. 5 is inserted toextrude the mixed mass.

As is known, for more uniform mixture dispensing, a pressurized airsystem can be coupled to the syringe. This is achieved by inserting ashankless plunger in the barrel open end, and then attaching a suitableair-valve to the open end of the'barrel using its flange to hold theair-valve in place. A supply of pressurized air is coupled to theair-valve. On pressing the air-valve actuator, -air under controlledpressure pushes the plunger uniformly into the barrel expelling themixture from the orifice.

Ashas been mentioned above, the invention is generally applicable to anytwo-component mixture which requires component separation up until themoment of use, and then intimate contact of the components in roughlyequal proportions in the device enabling rapid and controlled dispensingwhere desired. Typically, the components will be of the liquid type thatundergo a chemical reaction when brought into contact with one another;The device of the invention is best suited for heavy components becausethese are the most difficult to mix by the prior art constructions andalso the heavier the components the smaller risk of leakage between thetwo compartments. In many of these mixpartments are of the same size,thedevice of the invention is best suited for mixing roughly equalproportions of constituents, but it is also possible to use same to makemixtures involving varying amounts of the different constituents.

While the closure 16 has been described as a cup, the invention'is notlimited thereto, and any form'of slotted closure or stopper can beemployed. For instance, the closure 16 can be a stopper similar to theplunger-27 of FIG. 5 with a slot in'the center to accommodate thecenterboard. With a stopper of resilient material, an advantage is thatit seals off the open end of the syringe and will also seal against thecenterboard, thereby eliminating the need of an additional seal on top.The stopper is removed with the centerboard for later insertion of themixing tool. I

Also, the bottom of the syringe 7 need. not be funnelled down toa smallorifice. For mixing very heavy materials, the bottom piece 7 can be madein the form of .a detachable cap which'is removed after mixing to makeavailable at the bottom an opening having the full widthof the syringefor extruding the heavy materials.

While the principles of the invention have now been made clear inseveral illustrative embodiments, there willbe immediately obvious tothose skilledin the art many modifications in structure, arrangementproportions, the elements, materials, and components, used in thepractice of the invention, andotherwise, which are particularly adaptedfor specific environments and operating requirements, without departingfrom those principles. The appended claims are therefore intended tocover and embrace. any such modifications, within the limits only of thetrue spirit and scope of the invention.

What is claimed is:

1. A disposable syringe and mixing assembly comprising a syringebarrelhaving a closed exiting orifice at one end and an opening at theopposite end, a removable centerboard disposed in the barrel andengaging the barrel walls and forming two side-by-sidecompartments eachfor receiving one of two components of a mixture to be formed, and aclosure mounted at the opening at the opposite-end of the syringebarrel, said r} closure having a slot, said centerboard extendingthrough said slot.-

2. A disposable syringe and mixing assembly as claimedin claim 1, andfurther including means for mixing the two constituents after removal ofthe centerboard, and means for expelling the mixture. from the exitingorifice.

3. A disposable syringe and mixing assembly as claimed in claim 1wherein the exiting orifice is small and the opposite end opening islarger, and the centerboard closes off the orifice.

4. A syringe and mixing assembly as claimed in claim 3 wherein theopposite end of the barrel has a flange, and the closure has a flangeadapted to seat on the barrel flange.

5. A syringe and mixing assembly as set forth in claim 4 wherein theclosure is of foil and further comprises a portion depending from theflange and adapted to seat within the barrel opening.

6. A syringe and mixing assembly as set forth in claim with the barrelinterior.

1. A disposable syringe and mixing assembly comprising a syringe barrelhaving a closed exiting orifice at one end and an opening at theopposite end, a removable centerboard disposed in the barrel andengaging the barrel walls and forming two side-by-side compartments eachfor receiving one of two components of a mixture to be formed, and aclosure mounted at the opening at the opposite end of the syringebarrel, said closure having a slot, said centerboard extending throughsaid slot.
 2. A disposable syringe and mixing assembly as claimed inclaim 1, and further including means for mixing the two constituentsafter removal of the centerboard, and means for expelling the mixturefrom the exiting orifice.
 3. A disposable syringe and mixing assembly asclaimed in claim 1 wherein the exiting orifice is small and the oppositeend opening is larger, and the centerboard closes off the orifice.
 4. Asyringe and mixing assembly as claimed in claim 3 wherein the oppositeend of the barrel has a flange, and the closure has a flange adapted toseat on the barrel flange.
 5. A syringe and mixing assembly as set forthin claim 4 wherein the closure is of foil and further comprises aportion depending from the flange and adapted to seat within the barrelopening.
 6. A syringe and mixing assembly as set forth in claim 2wherein the closure slot closely fits the centerboard whereby theclosure functions to wipe the centerboard during its removal.
 7. Asyringe and mixing assembly as set forth in claim 6 wherein a smallprotuberance is located at the bottom of the centerboard and functionsto engage and lift off the closure during removal of the centerboard. 8.A syringe and mixing assembly as set forth in claim 2 and furthercomprising a paddle tool adapted for insertion into the barrel, and aplunger for engagement with the barrel interior.